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1.
Mar Pollut Bull ; 159: 111484, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32892919

RESUMO

In this study a novel sustainable method based on supercritical fluid extraction (SFE) method was developed for simultaneous extraction and fractionation of petroleum biomarkers. We herein proposed a two-step supercritical fluid extraction method for crude oil and tar ball to separate the petroleum biomarkers into aliphatic and aromatic fractions. In the first step, pure scCO2 was used, while scCO2 modified was used as a solvent in the subsequent step. CO2 SFE can serve as an environmental-friendly alternative to common column chromatography method for petroleum biomarker or compositional analysis by GC-MS. The extraction process was shown to be selective, according to the polarity of the solvent, providing fractionation of aliphatic and aromatic hydrocarbons. Yet the total extraction procedure in SFE was significantly faster than column chromatography methods (~80 min vs. 8 h). We will discuss the implications of this SFE method as a novel sustainable alternative to the existing extraction techniques.


Assuntos
Cromatografia com Fluido Supercrítico , Petróleo/análise , Biomarcadores , Fracionamento Químico , Cromatografia Gasosa-Espectrometria de Massas
2.
Molecules ; 25(17)2020 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-32872217

RESUMO

A pandemic caused by the novel coronavirus (SARS-CoV-2 or COVID-19) began in December 2019 in Wuhan, China, and the number of newly reported cases continues to increase. More than 19.7 million cases have been reported globally and about 728,000 have died as of this writing (10 August 2020). Recently, it has been confirmed that the SARS-CoV-2 main protease (Mpro) enzyme is responsible not only for viral reproduction but also impedes host immune responses. The Mpro provides a highly favorable pharmacological target for the discovery and design of inhibitors. Currently, no specific therapies are available, and investigations into the treatment of COVID-19 are lacking. Therefore, herein, we analyzed the bioactive phytocompounds isolated by gas chromatography-mass spectroscopy (GC-MS) from Tinospora crispa as potential COVID-19 Mpro inhibitors, using molecular docking study. Our analyses unveiled that the top nine hits might serve as potential anti-SARS-CoV-2 lead molecules, with three of them exerting biological activity and warranting further optimization and drug development to combat COVID-19.


Assuntos
Antivirais/química , Betacoronavirus/química , Compostos Fitoquímicos/química , Inibidores de Proteases/química , Tinospora/química , Proteínas não Estruturais Virais/antagonistas & inibidores , Antivirais/classificação , Antivirais/isolamento & purificação , Antivirais/farmacologia , Betacoronavirus/efeitos dos fármacos , Betacoronavirus/enzimologia , Domínio Catalítico , Infecções por Coronavirus/tratamento farmacológico , Cisteína Endopeptidases/química , Cisteína Endopeptidases/genética , Cisteína Endopeptidases/metabolismo , Descoberta de Drogas , Cromatografia Gasosa-Espectrometria de Massas , Expressão Gênica , Humanos , Cinética , Simulação de Acoplamento Molecular , Pandemias , Compostos Fitoquímicos/classificação , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Pneumonia Viral/tratamento farmacológico , Inibidores de Proteases/classificação , Inibidores de Proteases/isolamento & purificação , Inibidores de Proteases/farmacologia , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Estrutura Secundária de Proteína , Especificidade por Substrato , Termodinâmica , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo
3.
Chemosphere ; 258: 127367, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32947676

RESUMO

Due to their important roles in salt-producing acid-base reactions, new particle formation (NPF), and as precursors in secondary organic aerosol (SOA) producing reactions, the atmospheric concentrations of particulate volatile amines (dimethylamine (DMA), ethylamine, diethylamine (DEA), propylamine, and butylamine) at Seoul were analyzed and evaluated. To quantify the presence of volatile amines in particulate matter with aerodynamic diameters less than or equal to a nominal 2.5 µm (PM2.5), an efficient and rapid analytical method based on in-matrix ethyl chloroformate (ECF) derivatization followed by headspace solid-phase microextraction (HS-SPME) was developed and validated using gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) in the multiple reaction monitoring (MRM) mode. The annual mean concentration of the total 5 target amines was 5.56±2.76 ng/m3 and the seasonal difference was small. The concentrations of particulate amines measured in this study were lower than those observed in Zongludak, Turkey, Nanjing, China, and Jeju, Korea but slightly higher than that reported in Kobe, Japan. The concentrations of the nitrosamines (nitrosodimethylamine (NDMA) and nitrosodiethylamine (NDEA)), and of the nitramines (dimethylnitramine (DMN) and diethylnitramine (DEN)) measured along with those of the target amines were used in a simple linear regression analysis. It indicates the contribution of DMA to the formation of NDMA in all seasons (except the fall) and DEA to the formation of NDEA in the summer, while DMA and DEA did not significantly contribute to the formation of nitramines.


Assuntos
Poluentes Atmosféricos/análise , Aminas/análise , Monitoramento Ambiental , China , Dietilnitrosamina , Dimetilaminas , Dimetilnitrosamina/análise , Etilaminas , Cromatografia Gasosa-Espectrometria de Massas/métodos , Nitrosaminas/análise , Material Particulado/análise , República da Coreia , Seul , Microextração em Fase Sólida/métodos , Espectrometria de Massas em Tandem
4.
Wei Sheng Yan Jiu ; 49(4): 603-612, 2020 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-32928352

RESUMO

OBJECTIVE: A method based on isotope internal standard dilution was established for the determination of four polycyclic aromatic hydrocarbons(PAH4) including chrysene, benzo [a] anthracene, benzo [b] fluoranthene and benzo [a] pyrene in spicy strips sold in the markets. METHODS: The hot strips were homogenized and the target compounds were extracted with n-hexane, concentrated in vacuum, saponified and purified by solid phase extraction column, then the pretreated samples were separated by DB-EUPAH column(20 m×0. 18 mm, 0. 14 µm), detected by gas chromatography-mass spectrometry(GC-MS)and quantified by internal standard of isotope. RESULTS: The recoveries of PAH4 in different concentration levels of hot noodles were 91. 0%-103. 5%, and the relative standard deviation(RSD)was 1. 89%-6. 73%(n=6). The detection limit was 0. 30 µg/kg and the quantitative limit was 1. 0 µg/kg. The content of PAH4(sum) in 27 collected samples ranged from 1. 35 µg/kg to 11. 44 µg/kg, and the detection rate was 100%. CONCLUSION: With less solvent consumption, good purification effect and blank control, the method is simple, rapid and accurate and meets the detecting requirements of PAH4 in hot strips.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos/análise , Cromatografia Gasosa-Espectrometria de Massas , Isótopos , Espectrometria de Massas , Vácuo
5.
Zhongguo Zhong Yao Za Zhi ; 45(16): 3857-3862, 2020 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-32893581

RESUMO

Licorice is one of the most commonly used traditional Chinese medicine. In clinic, raw licorice and honey-fried licorice are used in medicines, with the main effects in clearing away heat and detoxifying, moistening lungs and removing phlegm. Honey-fried licorice has effects in nourishing the spleen and stomach and replenishing Qi and pulse. Because traditional Chinese medicine exerts the effects through multiple components and multiple targets, the index components used in the quality evaluation of licorice are often difficult to reflect their real quality. In addition, most of studies for the quality standards have shown that honey-fried licorice are the same as licorice, with a lack of quality evaluation standards that can demonstrate their processing characteristics. The quality of medicine is directly related to its clinical efficacy, so it is necessary to establish a more effective quality control method. Licorice has a beany smell, which is one of the main quality identification characteristics. In this study, by taking advantage of the odor characteristics, a headspace-gas chromatography-ion migration mass spectrometry technology was used to establish a quality evaluation method. A total of 76 volatile components were identified. Through the dynamic principal component analysis, 7 kinds of volatile substances in raw licorice and 13 kinds of volatile substances in honey-fried licorice were statistically obtained, and could be taken as index components for the quality evaluation of raw and honey-fried licorice, respectively. This study could help realize the combination and unification of modern detection and traditional quality evaluation methods, and make a more realistic evaluation for the quality of licorice.


Assuntos
Glycyrrhiza , Mel/análise , Compostos Orgânicos Voláteis/análise , Cromatografia Gasosa-Espectrometria de Massas , Espectrometria de Mobilidade Iônica
6.
Georgian Med News ; (304-305): 153-157, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32965267

RESUMO

The research objectives were to study the introduction process of different aromatic and spice plants in the Batumi Botanical Garden and the content of bioactive compounds in aromatic plants introduced and grown in the soil and climatic conditions of the garden.; Among the aromatic plants introduced to the BBG by the authors, the following species are having full vegetative and generative development in the open ground:Cuminum cyminum L.; Polianthes tuberosa L.; Iris pallida Lam.;Geranium macrorrhizum L., Piper suaveolens Ham., Piper piperita L., Thymus citriodorus Schreb., Satureja Montana L., Mentha piperita L., Origanum vulgare L., Mentha longifolia L., Hyssopus officinalis L.; Phyla scaberrima Moldenke, Ruta graveolens L.; Vegetative organs reach the full development, but without blooming:Curcuma longa L..; Zingiber officinale Roscoe.; Elettaria cardamomum Maton.; Coffea arabica L.; Coffea conephera L..; Vanilla planifolia Jacks.; Cassia acutifolia Delile.; For the purpose of studying the content of bioactive compounds in plants introduced to the soil and climatic conditions of the BBG with the help of green technologies, the following species were taken for analysis:Cassia acutifolia Delile. - seed, flower, leaf; Cuminum cyminum L. - seed; Coffea conefera L. andCoffea Arabica L., leaves and seeds; Vanilla planifolia Jacks. - leaves; Elletaria cardamomum Maton. -Cardamom leaves.With the help of gas chromatography - mass spectrometry GC-MS method, there were identified bioactive compounds of various classes. The content of essential oils is identified in all research objects.


Assuntos
Óleos Voláteis , Satureja , Jardins , Cromatografia Gasosa-Espectrometria de Massas , Folhas de Planta
7.
J Chromatogr A ; 1628: 461445, 2020 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-32822984

RESUMO

Anabolic androgenic steroids (AAS) have been the most commonly abused substances taken by not only professional sportsmen but also recreational bodybuilders. The detection of micro-dose testosterone (T) misuse is particularly challenging as it possesses pseudo-endogenous origin and is sometimes impossible to be identified in urine samples. Dried blood (DB) obtained by finger pricking has been proven to be an alternative matrix for better correlating to physiological responses. Moreover, the introduction of the volumetric absorptive microsampling (VAMS) technology allows overcoming some major limitations of spotting blood onto a filter paper card. In this work, a fast and sensitive GC-MS/MS method was developed and validated for the quantification of AAS in DB collected by means of VAMS. T and the eight top abused synthetic AAS, namely nandrolone, boldenone, mesterolone, drostanolone, metenolone, metandienone, oxandrolone, and dehydrochloromethyl T were selected as the target analytes. The method based on VAMS exhibited good precision, accuracy as well as stability, and superior extraction recoveries over the punched DB spots reported in the literature. The chromatographic separation was achieved within 6.4 min and the detection limit is as little as 50 fg (i.e. able to detect 0.10 ng mL-1 in 20 µL of DB). Confirmed by forty real blood samples, the Deming regression and Bland-Altman analysis revealed that the VAMS DB could be employed for quantifying blood T level in agreement with using the serum specimen. The feasibility of the method was then successfully proven by the analysis of samples collected from a three-arm T administration trial. Our results highlighted that DB total T was a sensitive indicator for identifying transdermal micro-dosing of T. In the groups of receiving T gel administration, T concentrations could rise up to ten times higher than the baseline at 9 h after the application. As a future step, this approach is being expanded to a large cohort screening of bodybuilders at gym and ultimately may allow universal applications on monitoring sports drug misuse.


Assuntos
Androgênios/sangue , Teste em Amostras de Sangue Seco/métodos , Monitoramento de Medicamentos/métodos , Cromatografia Gasosa-Espectrometria de Massas , Espectrometria de Massas em Tandem , Congêneres da Testosterona/sangue , Testosterona/análise , Humanos
8.
Environ Monit Assess ; 192(9): 564, 2020 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-32757090

RESUMO

The inventories and the possible mechanisms behind the relative deficiency of both radium and uranium release processes within an elevated gamma-anomalous rock were investigated. A field survey was performed on the highest radioactive anomalous zone that was recorded at Jabal Al Alam (20° 13' 10.06″ N and 44° 14' 32.13″), with the ferruginous sandstone, iron oxide band, and iron concretions (with uranium content and reaching up to1500 ppm). The chemical analyses and the laboratory's gamma-ray spectrometric measurements demonstrated high uranium levels in the analyzed rock samples of the Wajid Sandstone (up to 1000 ppm). The borehole geophysical logs further confirmed that the radioactive anomalies are attributed to the sandstone sequence of the Wajid Formation that is often found associated with elevated concentrations of uranium. The groundwater samples taken from the wells tapping the Wajid aquifer showed uranium concentrations ranging from 0.01 to 5.5 ppb (µg/L). The average 226Ra in groundwater samples was 0.2 Bq L-1. The majority of the 226Ra and 228Ra activities were below the lower limit of detection (LLD). The radiochemical analyses of water samples from the Wajid aquifer display low concentrations of both uranium and 226Ra, with relation to uranium content in host rocks. This was attributed to the fact that uranium is susceptible to form iron oxide complexes, causing them to precipitate in a more stable form. Furthermore, iron oxides coat the sand grains of the Wajid Formation and accordingly might act as a foundation for re-adsorption for both uranium and radium, resulting in their relative deficiency in the surrounding water. The coating might also act as a physical barrier resulting in hindrance of the recoil nuclei due to its significant thickness (several orders of magnitude) compared with that of the average (120 nm) whole alpha-recoil track (ART). The coating layer thickness was determined via scanning electron microscopy (SEM) and was found to be up to 180 µm.


Assuntos
Água Subterrânea , Monitoramento de Radiação , Rádio (Elemento)/análise , Urânio/análise , Poluentes Radioativos da Água/análise , Monitoramento Ambiental , Cromatografia Gasosa-Espectrometria de Massas , Arábia Saudita
10.
Sci Total Environ ; 743: 140495, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32758811

RESUMO

The Inuit of Nunavik (Northern Quebec, Canada) are exposed to polychlorinated biphenyls (PCBs) and mercury (Hg) through their consumption of marine country foods. A temporal trend study was initiated in 1992 to monitor circulating levels of PCBs and Hg in pregnant Inuit women, since the fetus is most at risk of adverse health effects. We set out (1) to describe temporal trends of PCBs and Hg levels in pregnant Nunavik women between 1992 and 2017; (2) to determine the prevalence of participants exceeding the guidance values in 2017; (3) to investigate relations between marine country food intake and contaminant levels over the study period. A total of 559 pregnant women provided a blood sample for contaminant analysis from 1992 to 2017. PCB congeners were quantified in plasma (serum) by gas chromatography (GC) coupled to electron capture detection or mass spectrometry (MS). We determined whole blood mercury concentration by cold vapor atomic absorption or inductively-coupled plasma MS. We performed multilevel modeling to assess temporal trends in contaminant levels and relations with marine country food consumption. Concentrations of total PCBs and Hg decreased by 84% and 65% between 1992 and 2017, respectively. Nevertheless, 10% and 22% of women in 2017 exceeded guidance values for PCBs and Hg, respectively. While the decline in marine country food intake is the only factor associated with decreasing Hg levels, other factors may explain the decline in PCB levels. Despite the significant decline in PCBs and Hg levels from 1992 to 2017, exposure to these contaminants is still quite prevalent among pregnant Nunavik women. Most of the decline in Hg exposure is likely due to a shift away from marine country foods to store-bought foods, which is a concern given the cultural and nutritional importance of country foods and the high food insecurity that prevails in Nunavik.


Assuntos
Poluentes Ambientais/análise , Mercúrio , Bifenilos Policlorados/análise , Canadá , Exposição Ambiental , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Inuítes , Gravidez , Quebeque
11.
Ecotoxicol Environ Saf ; 202: 110910, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800245

RESUMO

Microplastics (MPs) are ubiquitous in the environment and more abundant in the marine environment. Consequently, increasing focus has been put on MPs in oceans and seas, while little importance has been attached to their presence in freshwaters and soils. Therefore, this paper aimed to provide a comprehensive review of the occurrence, analysis and ecotoxicology of MPs. The abundance and distribution of MPs in several typical freshwater systems of China were summarized. It suggested that the surface water of Poyang Lake contained the highest concentration of 34 items/L MPs among all the 8 freshwater systems, and the content of MPs in sediments were higher than that of the surface water. Net-based zooplankton sampling methods are the most frequently utilized sampling methods for MPs, and density separation, elutriation and digestion are three major pretreatment methods. Fourier transform infrared spectroscopy, Raman spectroscopy and pyrolysis-gas chromatography coupled to mass spectrometry are often used to identify the polymer types of MPs. Besides, MPs might damage the digestive tract of various organisms and negatively inhibit their growth, feeding and reproduction. The ways of human exposure to MPs are by ingestion, inhalation and dermal exposure, digestive and respiratory system might be adversely influenced. However, potential health risks of MPs to humans are remained insufficiently researched. Overall, by showing the presence of MPs in freshwaters and soils as well as possible ecotoxicological effects on the environment and humans, this paper provided a framework for future research in this field.


Assuntos
Monitoramento Ambiental , Poluentes Ambientais/análise , Microplásticos/análise , Animais , China , Ecotoxicologia , Monitoramento Ambiental/métodos , Poluentes Ambientais/toxicidade , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Lagos/química , Microplásticos/toxicidade , Oceanos e Mares , Plásticos/química , Solo , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/análise , Zooplâncton
12.
J Chromatogr A ; 1626: 461389, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797860

RESUMO

The reliable measurement of very volatile organic compounds (VVOC) in indoor air by use of thermal desorption gas chromatography (TD-GC) in order to include them into evaluation schemes for building products even nowadays is a great challenge. For capturing these small molecules with carbon numbers ranging from C1C6, strong adsorbents are needed. In the present study, recovery rates of nine suitable adsorbents of the groups of porous polymers, graphitised carbon blacks (GCB) and carbon molecular sieves (CMS) are tested against a complex test gas standard containing 29 VVOC. By consideration of the recovery and the relative humidity (50% RH), combinations of the GCB Carbograph 5TD, the two CMS Carboxen 1003 and Carbosieve SII as well as the porous polymer Tenax® GR were identified to be potentially suitable for sampling the majority of the VVOC out of the gas mix. The results reveal a better performance of the adsorbents in combination than being used alone, particularly under humid sampling conditions. The recovery rates of the chosen compounds on each adsorbent should be in the range of 80-120%.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Compostos Orgânicos Voláteis/análise , Adsorção , Carbono/química , Gases/química , Umidade , Polímeros/química , Temperatura
13.
J Chromatogr A ; 1627: 461404, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32823109

RESUMO

Liamocin biosurfactants and structurally related exophilins secreted by the Aureobasidium pullulans (A. pullulans) strain NRRL62031 were firstly analyzed by hyphenation of high-performance liquid chromatography (HPLC) with high-resolution mass spectrometry (HRMS). Ten different analytes were detected and identified by their accurate masses and divided into subclasses according to their different head groups: three liamocins with arabitol as head group, three mannitol liamocins, and four exophilins. A baseline separation of congeners within the subclasses was achieved by reversed phase HPLC on a C18 stationary phase, whereas an overlap of subclasses occurred. The structures were simultaneously confirmed by online tandem mass spectrometry (MS/MS) experiments in positive and negative ionization mode. The assigned polyol head groups and thus the feasibility of this method were confirmed by gas chromatography (GC)-MS data obtained after hydrolysis and derivatization of the liamocins. Based on the varying structural characteristics of liamocins, e.g. the polyol head group (or even none for exophilins) and the degree of acetylation, different detector response in LC-MS was expected, impairing relative quantification of congeners. Therefore, a complementary quantification method was developed using HPLC coupled to charged-aerosol detection (CAD), which allows the determination of the amount of the individual liamocin species without authentic liamocin standards. Hence, the here presented hyphenated techniques facilitate comprehensive analysis of liamocin biosurfactants.


Assuntos
Aerossóis/análise , Cromatografia de Fase Reversa/métodos , Manitol/análise , Tensoativos/análise , Espectrometria de Massas em Tandem , Ascomicetos/química , Cromatografia Líquida de Alta Pressão , Cromatografia Gasosa-Espectrometria de Massas , Manitol/química , Álcoois Açúcares/análise , Álcoois Açúcares/química
14.
J Chromatogr A ; 1627: 461416, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32823114

RESUMO

Animal feeds are often reported to be contaminated with chemical residues, and when present above the maximum legal limit, these compounds can cause harmful effects to consumers of animal produce. Thus, animal feed safety is an important regulatory concern. The aim of this study was to optimise a multiresidue method for the simultaneous analysis of multi-class pesticides and a number of frequently used veterinary drugs using LC-MS/MS and GC-MS/MS. The method was validated in a range of feed matrices, including maize feed, poultry feed and mixed feed concentrate. The optimised sample preparation workflow involved extraction of feeds (5 g) with ethyl acetate (10 mL), followed by a freezing step (at -20°C) used for eliminating the matrix co-extractives. The extract was further cleaned by dispersive solid phase extraction with a combination of primary secondary amine, C18 and florisil sorbents. From the cleaned-extract, an aliquot was analysed by GC-MS/MS, while another portion of it was solvent-exchanged to acetonitrile:water (50:50) and then analysed by LC-MS/MS. This method effectively minimised the matrix interferences. A total of 192 pesticides was analysed by GC-MS/MS within a runtime of 22 min. The LC-MS/MS method was validated for 187 compounds including 17 veterinary drugs. For most of the compounds, the limit of quantification (LOQ) was 0.01 mg/kg. The recoveries at LOQ and higher levels ranged between 70% and 120%, with precision-RSDs of < 20%. The method provided a precise analysis in a wide range of market-feed samples. As shown, the method is suitable for regulatory and commercial testing purposes.


Assuntos
Ração Animal/análise , Cromatografia Líquida/métodos , Praguicidas/análise , Espectrometria de Massas em Tandem/métodos , Drogas Veterinárias/análise , Animais , Congelamento , Cromatografia Gasosa-Espectrometria de Massas , Limite de Detecção , Resíduos de Praguicidas/análise , Reprodutibilidade dos Testes , Solventes/química , Água/química
15.
J Chromatogr A ; 1626: 461349, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797829

RESUMO

In the present work, a very sensitive and fully automated direct immersion PAL SPME Arrow procedure, coupled with GC-MS, has been developed and validated for determination of nine phosphorus flame retardants in different types of water samples (river, drinking and rainwater). PDMS/DVB was selected among three commercially available SPME Arrows (PDMS/DVB, DVB/PDMS/CWR and PDMS/CWR), since it resulted in the best sensitivity. The important experimental parameters were optimized via a central composite design response surface methodology and as result, extraction time of 65 min, extraction temperature of 80 °C and added salt concentration of 19% (w/v), were selected as the optimum values. The optimized method showed linear response over the calibration range (2 - 500 ng L-1), with R2-values higher than 0.9937. The precision (RSD%) measured by replicate analyses (n = 7) was estimated at 2 and 100 ng L-1 and was less than 29% and 21%, respectively. The LOQ of PAL SPME Arrow, calculated as S/N = 10, was between 0.2 and 1.2 ng L-1 (for triphenyl phosphate and tris-(1­chloro­2-propyl) phosphate, respectively) with extraction efficiencies between 5.9 and 31% (for tris-(1,3-dichloro-2-propyl) phosphate and tri-n­butyl phosphate, respectively). To assess the performance of the developed technique for real samples, two river water samples, tap water from two regions and a rainwater sample were analyzed. Most of the target analytes were observed in the river samples with concentrations of 1.0 - 250 ng L-1 and the obtained recoveries at 50 ng L-1 ranged between 60 and 107%. Considering the figures of merit of the optimized method, PAL SPME Arrow-GC-MS showed to be the most sensitive analytical approach for determination of phosphorus flame retardants in water, with satisfying precision and accuracy, compared with conventional SPME-NPD, LLE-GC-MS and SPE-LC-MS/MS.


Assuntos
Retardadores de Chama/análise , Fósforo/análise , Microextração em Fase Sólida/métodos , Poluentes Químicos da Água/análise , Automação , Dimetilpolisiloxanos/química , Cromatografia Gasosa-Espectrometria de Massas , Polivinil/química , Soluções
16.
J Chromatogr A ; 1626: 461356, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797836

RESUMO

The presence of organophosphate esters (OPEs) in everyday commodities such as furniture, household appliances and baby toys have rendered these contaminants ubiquitous in environmental fates such as air, water, soils and biota. Their presence in food-related species suggests that an additional route of exposure to these esters for the general population is fish intake through diet. Their incipient toxicity and carcinogenetic behaviour make it essential to develop methods for determining OPEs in fish samples. In this paper we have developed a new method for determining 9 OPEs based on the QuEChERS extraction method followed by a simple clean-up using a novel device for selective lipid removal (LipiFiltr) and GC-MS/MS to extract these compounds from fish samples regardless of lipid content. QuEChERS salt packet optimisation and clean-up strategies such as liquid-liquid extraction, dispersive-solid phase extraction and LipiFiltr were tested. Our results showed that EN 15662 method salts and Lipifiltr were the best combination to produce efficient analyte apparent recovery (67-116%) and negligible matrix effects (<10%). Limits of detection ranged from 0.05 ng g-1 (dry weight) for TiBP and TBP to 2.00 ng g-1 (dry weight) for TCEP. Fish samples from four fish species were determined with a median concentration of ΣOPEs 5.31 ng g-1 on a wet weight basis, with TBP, TiBP and TCPP as the main contenders. Estimates of exposure and risk associated with consuming these compounds via dietary intake showed low levels of concern for the population of Tarragona.


Assuntos
Ésteres/análise , Peixes/metabolismo , Retardadores de Chama/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Organofosfatos/análise , Plastificantes/análise , Medição de Risco , Espectrometria de Massas em Tandem , Adolescente , Adulto , Idoso , Animais , Criança , Dieta , Monitoramento Ambiental , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Espectrometria de Massas em Tandem/métodos , Adulto Jovem
17.
Environ Pollut ; 266(Pt 1): 115372, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32814266

RESUMO

Global concern exists regarding human exposure to organic pollutants derived from public open spaces and indoor dust. This study has evaluated the occurrence of 18 polycyclic aromatic hydrocarbons (PAHs), 11 organophosphorus flame retardants (OPFRs) and bisphenol A (BPA). To achieve this, a new simple, efficient and fast multi-residue analytical method based on a fully automated pressurised liquid extraction (PLE) and subsequent quantification by gas chromatography coupled to electron ionization-mass spectrometry (GC-EI-MS) in selected ion monitoring (SIM) mode was developed. The developed method was applied to indoor dust (12 sampling households) and soil derived from two public open spaces (POSs). Among all compounds studied, PAHs were the most ubiquitous contaminants detected in POS soils and indoor dust although some OPFRs and BPA were detected in lower concentrations. An assessment of the incremental lifetime cancer risk (ILCR) was done and indicated a high potential cancer risk from the POS sites and some of the indoor dust sampled sites. However, key variables, such as the actual exposure duration, frequency of contact and indoor cleaning protocols will significantly reduce the potential risk. Finally, the ingestion of soils and indoor dust contaminated with OPFRs and BPA was investigated and noted in almost all cases to be below the USEPA reference doses.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Retardadores de Chama/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Compostos Benzidrílicos , Poeira/análise , Exposição Ambiental/análise , Monitoramento Ambiental , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Organofosfatos/análise , Fenóis , Solo
18.
Curr Protoc Plant Biol ; 5(3): e20114, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32791571

RESUMO

Plant wax lipid molecules, chiefly normal (n-) alkanes and n-alkanoic acids, are frequently used as proxies for understanding paleoenvironmental and paleoclimatic change. These are regularly analyzed from marine and lake sediments and even more frequently in archaeological contexts, enabling the reconstruction of past environments in direct association with records of past human behavior. Carbon and hydrogen isotope measurements of these compounds are used to trace plant type and water-use efficiency, relative paleotemperature, precipitation, evapotranspiration of leaf and soil moisture, and other physiological and ecological parameters. Plant wax lipids have great potential for answering questions related to human-environment interactions, being for the most part chemically inert and easily recoverable in terrestrial sediments, including those dating back millions of years. The growing use of this technique, and comparison of such data with other paleoenvironmental proxies such as pollen and phytolith analysis and soil carbonate and tooth enamel isotope records, make it essential to establish consistent, best-practice protocols for extracting n-alkanes and n-alkanoic acids from archaeological sediments to provide comparable information for interpreting past climatic, ecosystem, and hydrological changes and their interaction with human societies. © 2020 The Authors. Basic Protocol 1: Total lipid extraction Support Protocol 1: Weighing the total lipid extract Support Protocol 2: Cleaning the PSE extraction cells Alternate Protocol 1: Soxhlet total lipid extraction Alternate Protocol 2: Ultrasonic total lipid extraction Basic Protocol 2: Separation of lipids by aminopropyl column chromatography Basic Protocol 3: Separation of lipids by silver-nitrate-infused silica gel column chromatography Support Protocol 3: Preparation of silica gel infused with 10% silver nitrate Basic Protocol 4: Methylation of n-alkanoic acids Basic Protocol 5: Gas chromatography mass spectrometry (GC-MS) Basic Protocol 6: Gas chromatography isotope ratio mass spectrometry (GC-IRMS).


Assuntos
Arqueologia , Ecossistema , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Lipídeos , Folhas de Planta
19.
Ann Biol Clin (Paris) ; 78(4): 417-424, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32753366

RESUMO

We present the case of a four-year-old girl, who was hospitalized in intensive care unit for a coma resulting from metabolic acidosis with increased anion gap. The patient was treated for short bowel syndrome, following necrotising enterocolitis, which occurred 51 days after birth. In our initial evaluation of the patient's metabolic acidosis, we were unable to identify the cause of the increased anion gap. Urinary organic acids chromatography identified a large peak of lactate (quantified at 15 mmol/mol of creatiniuria), as well as its metabolites. The discrepancy between normal blood lactate concentration assayed by enzymatic assay, and the large amount of lactate found by gas-chromatography/mass spectrometry (GC/MS) in urine highlights the limit of the stereospecificity of enzymatic assays. Indeed, most lactates assay use enzymatic assays that are specific for L-lactate, whereas organic acids chromatography, whose column is mostly achiral, can detect both stereoisomers, D- and L-lactate. Organic acids in urine analysis, in addition to the clinical context, suggested a diagnosis of D-lactic acidosis. Following a review of the physiopathology and treatment of short bowel syndrome, we will discuss the mechanism and diagnosis of the D-lactic acidosis in our patient. This case highlights the need to perform an organic acid profile in urine in the presence of any unexplained increased anion gap to determine its cause.


Assuntos
Equilíbrio Ácido-Base/fisiologia , Acidose Láctica/diagnóstico , Acidose/diagnóstico , Coma/diagnóstico , Síndrome do Intestino Curto/diagnóstico , Acidose/etiologia , Acidose/metabolismo , Acidose Láctica/etiologia , Acidose Láctica/metabolismo , Acidose Láctica/urina , Análise Química do Sangue/métodos , Pré-Escolar , Coma/sangue , Coma/etiologia , Coma/urina , Diagnóstico Diferencial , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Ácido Láctico/sangue , Ácido Láctico/urina , Síndrome do Intestino Curto/complicações , Síndrome do Intestino Curto/metabolismo , Urinálise
20.
Bull Environ Contam Toxicol ; 105(3): 460-467, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32839840

RESUMO

A green, sensitive and accurate dispersive liquid-liquid microextraction (DLLME) method was used to preconcentrate four selected pesticides in dam lake water samples for determination by gas chromatography-mass spectrometry (GC-MS). Conditions of the DLLME method were comprehensively investigated and optimized according to type/volume of extraction solvent, type/volume of dispersive solvent, and type/period of mixing. The developed method was validated according to the limits of detection and quantitation, accuracy, precision and linearity. Under the optimum conditions, limit of detection values calculated for alachlor, acetochlor, metolachlor and fenthion were 1.7, 1.7, 0.2 and 7.8 µg/kg (mass based), respectively. The method recorded 202, 104, 275 and 165 folds improvement in detection power values for acetochlor, alachlor, metolachlor and fenthion, respectively, when compared with direct GC-MS measurements. In order to evaluate the accuracy of the developed method, real sample application with spiking experiments was performed on dam lake water samples, and satisfactory percent recovery results in the range of 81%-120% were obtained.


Assuntos
Microextração em Fase Líquida/métodos , Praguicidas/análise , Poluentes Químicos da Água/análise , Acetamidas/análise , Fention/análise , Água Doce/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Limite de Detecção , Solventes/análise , Toluidinas/análise
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